Transparent Light‐Driven Hydrogel Actuator Based on Photothermal Marangoni Effect and Buoyancy Flow for Three‐Dimensional Motion

Abstract

Marangoni-effect-driven actuators (MDAs) have the advantages of direct light-to-work conversion and convenient operation, which makes it widely researched in the cutting-edge fields including robots, micromachines, and intelligent systems. However, the MDA relies on the surface tension difference and it only works on the 2D liquid-air interface. Besides, the MDAs are normally pure black due to the light-absorption material limitation. Herein, a transparent light-driven 3D movable actuator (LTMA) and a 3D manipulation strategy are proposed. The LTMA is composed of photothermal nanoparticles-doped temperature-responsive hydrogel, whose surface energy changes as the nanoparticles absorb light energy. The 3D manipulation strategy combines Marangoni effect with photothermal buoyancy flow for realizing complex self-propellant and floating/sinking motions. The LTMA can perform more advanced tasks such as 3D obstacle avoidance and 3D sampling. Benefiting from the porous structure of hydrogel, LTMA can naturally absorb the chemical molecules for remote sampling and automated drug delivery. The light-driven, transparent, three-dimensionally movable, and programmable actuator has promising prospects in the field of micromachines and intelligent systems.

Multimotion of Marangoni Propulsion Ships Controlled by Two-Wavelength Near-Infrared Light

“…The momentum of the polyacrylamide and silicone ships irradiated at 980 nm seemed to be larger than that of the polyacrylamide and silicone ships at 808 nm. Hydrophobic or superhydrophobic materials are popular choices for Marangoni propulsion ships because of the expected reduction in water resistance. − Interestingly, despite large differences in wettability, we observed almost no difference in the momentum or decay time (10–20 s) of the polyacrylamide- and silicone-based ships on the water. The frictional resistance of the ship on the water surface will differ depending on whether the ship surface is hydrophobic or hydrophilic, but this difference is likely small because of the relatively slow movement.…”

“…Researchers have designed Marangoni propulsion ships in terms of shape, inner structure, and wettability to induce various locomotions, such as up and down in water, rotation in water droplets, and vibration near water droplets . Recently, material-diffusing , and photoresponsive − liquid marbles were also demonstrated as a Marangoni propulsion ship. These Marangoni ships, which incorporate photothermal conversion materials, have allowed the on/off switching of only one action to be achieved.…”

Tethered and Untethered 3D Microactuators Fabricated by Two-Photon Polymerization: A Review

“…Light plays a very important role in both the manufacturing and the manipulation of microstructures [57,[74][75][76]. Light is a pure and safe energy source that can be transmitted to target objects in a noncontact manner, which enables remote control [77][78][79][80]. It is well known that optical tweezers have been widely used to manipulate objects of different sizes, a process which received the Nobel prize in 2018.…”

Visible Light-Driven Jellyfish-like Miniature Swimming Soft Robot

“…To tackle the aforementioned inadequacies associated with jellyfish-like robots, a jellyfish-like miniature soft robot (JMSR) driven by visible light is proposed in this study. Light-powered actuators have the advantages of untethered actuation, remote control, and no contact with actuators. , Pan et al proposed a transparent light-driven 3D movable actuator which performed advanced tasks such as 3D obstacle avoidance and 3D sampling . This work is the first to develop a transparent light-driven actuator based on the Marangoni effect, which is of great significance.…”

“…20,21 Pan et al proposed a transparent light-driven 3D movable actuator which performed advanced tasks such as 3D obstacle avoidance and 3D sampling. 22 This work is the first to develop a transparent light-driven actuator based on the Marangoni effect, which is of great significance. Pan et al presented a soft actuator capable of realizing "diving" and "surfing" locomotion driven by light.…”